1. Field of the Invention
The present invention relates to an apparatus which measures a retinal function by photographing a fundus.
2. Description of Related Art
There is known an apparatus (system) which noninvasively performs imaging of a retinal function (see International Publication No. WO 00/06015 (Japanese Patent Application Unexamined Publication No. 2002-521115)). The apparatus includes an imaging illumination device which illuminates a retina, a stimulating illumination device which guides a functional response of the retina, and an imaging device which photo-receives light from the retina via an imaging optical system, measures the retinal function based on states of retinal images before/after irradiation of stimulating light onto the retina, and performs imaging of a result of the measurement for evaluation.
Such an apparatus reads a change of brightness of the retinal image after the irradiation of the stimulating light with respect to brightness of the retinal image before the irradiation of the simulating light; however, since a change of the retina (a change of an activity of nervous tissue) by the stimulating light is minute, it is important to detect the change accurately. In addition, in order to perform more precise measurement of the retinal function, it is necessary to perform the measurement over a depth direction of the retina.